† The Chemical Abstracts Service (CAS) Registry Number (CAS RN) is the property of the American Chemical Society and any use or redistribution, except as required in supporting regulatory requirements and/or for reports to the Government when the information and the reports are required by law or administrative policy, is not permitted without the prior, written permission of the American Chemical Society.

* Specifies that no single CAS RN applies to this substance.

**Threshold Category Descriptions:

Part 1A: A report is required for one or more substances if they were manufactured, processed or otherwise used (MPO) at a facility at a concentration ≥ 1% by weight (except for by-products and mine tailings) and in a quantity of 10 tonnes or more, and employees worked 20,000 hours or more at a facility.

Part 1B: A report is required for substances if they were manufactured, processed or otherwise used at a facility in quantities equal to or exceeding quantity and concentration thresholds, and employees worked 20,000 hours or more at a facility. The concentration threshold is not applicable for by-products or tailings/waste rock.

Part 2: A report is required for substances if polycyclic aromatic hydrocarbons (PAHs) were incidentally manufactured or present in mine tailings, and released, disposed or transferred from a facility in a combined quantity of50 kilogramsor more, and employees worked 20,000 hours or more at a facility. Wood preservation facilities using creosote must report regardless of the reporting threshold for PAHs and regardless of the number of hours worked by employees.

Part 3: A report is required for substances if a facility was engaged in specific activities.

Part 4: All facilities are required to consider Criteria Air Contaminants (CACs) released from stationary combustion equipment regardless of the number of employees at the facility. Additionally, facilities with greater than 20,000 employee hours must also consider all other sources of CACs at the facility.

Part 5: A report is required for any of the 75 listed Volatile Organic Compounds (VOCs) (including individual substances, isomer groups and other groups and mixtures) if they were released to air in a quantity of 1 tonne or greater and the 10 tonne air release threshold for VOCs (under Part 4) was met.

Substance Notes:

1 Total of the acid or base and its salts, expressed as the molecular weight of the acid or base. The CAS RN corresponds to the weak acid or base.

17 Total of pure lead and the equivalent weight of lead contained in any compound, alloy or mixture. Excludes lead (and its compounds) contained in stainless steel, brass or bronze alloys and lead contained in tetraethyl lead (CAS RN 78-00-2).

18 Particulate matter with a diameter less than or equal to 2.5 micrometres.